Railway and like signaling.



R. W. TARRANT.

RAILWIAY AND LIKE SIGNALING. APPLICATION FILED FEB. 12. ms.

1,280,582. Patented Oct. 1, i918.

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REUBEN WILLIAM TARRANT, OF LONDON, ENGLAND.

RAILWAY AND LIKE SIGNALING.

Specification of Letters latent.

Patented Oct. 1, 1918.

Application filed February 12, 1916. 7 Serial No. 77,846.

To all whom it may concern:

Be it known that I, REUBEN WILLIAM TARRANT, a subject of the King of Great Britain, and resident of 26 Voltaire road,

Clapham, London, England, have invented certain new and useful Improvements in Railway and like Signaling, of which the following is a specification.

This invention relates to an improved railcircuit system of electric control for railway trafiic, consisting of two distinct so-called rail-circuits whereof the individual trackrails respectively form parts series with the respective windings of a relay having two separate windings; said rail-circuits being, normally, mutually independent and supplied with current from a single source, and the circuit of said source being closed through both track-rails in series with one another only when said rails are connected together electrically, as for example in conseqluence of the presence of a train upon the ra1 s.

The improved system comprises, for each block-section of the line, arelay having two separate windings one end of each of which is connected to a source of current through one of the track-rails of the block-section, whiletheother end of each winding is connected to said source by a separate wire; the arrangement being such that the magnetic fields normally produced by the energization of the respective windings cooperate so as to maintain the controlled signal in a predetermined condition (say, line clear), Whereas, on the occurrence of abnormal current-conditions within the system, the effect of the resultant magnetic field or fields (if any) is such that reversal of the condition of the controlled signal (which will now indicate, say, line blocked) is concurrently brought about.

The relay above referred to may be regarded as constituting either an electric motor, or a relay such as, for example, that described in the specification of LettersPatent offlthe- United States 1,168,438 dated'Janw M 18,1916. 1 In the accompanying drawing, which illustrates diagrammatically one arrangementembodying the present invention as'applied I to a single block-section of a line of raila, b are therails' of the track within the way, Figure 1 indicates the conditions normally existingvinthe system, andFig. 2 indicates the conditions resulting from the entrance of a traininto the block-section.

block-section illustrated. a are the coils of one winding of the relay, and d are the coils of the other winding of the same. The polepieces al of the winding 03 are stationary, whereas the pole-pieces, c of the winding 0 are pivoted so as to be movable toward and from the stationary pole-pieces d and tend to approach the latter under gravity or spring-pressure. e is a source of current (hereinafter referred to as the battery, but it might be any other source of current, di-

rect or alternating) for energizing the windings o and d, this source being placed toward one end of the block-section and the relay toward the opposite end. i

One pole (say, the positive pole) of the battery e is connected by a wire 11, to the rail a at or near the adjacent extremity of the section, the same rail being connected, at or near the opposite extremity of the sec tion, bya wire 12 to one end of the winding d of the relay; while the other end of this winding is connected by a wire d to the oppositepole (say, the negative pole) of the battery 6. This latter pole of the battery is connected by a wire 13 to the rail 2) at or near the adjacent extremity of the section,

the same rall being connected, at or near the opposlte extremity of the section, by a wire 14 to one end of thewinding c of the relay; while the other end of this winding is connected by an insulated wire 0 to the first-mentioned (or positive) pole' of the battery 6." p I f is an electrically'actuated or governed signal commandingthe admission of traflic to the block-section, the electric circuit upon V which the condition of the signal is depend ent belng indicated as fed from a battery or other source g. In the circuit of this battery and the signal are interposed two of the winding 0 of the relay that, so long as both the pole-pieces c are held apart from the stationary pole-pieces d of the "switches hand j, which are respectively so controlled by V the movable pole-pieces 0 winding (5, the switcheslz; and j are closed and the "circuit of the battery 9 and signal f isclosed and the signal is thus held at line clear as indicated in Fig. 1'; whereas, on either or both of the pole-pieces 0 approaching the pole-pieces dflthe circuit of the battery 9 and signal f is broken at'either,

or both of the switches h and j, nalisth'u's put to line blocked in'Fig. 2. r V is (Fig. 2) indicates an axle and pair of and the. sigas indicated serving to connect together electrically the;

wheels of a traininthe block-section and rails a and b.

m is a resistance interposed between the battery 6 and the rail a for the purpose ofpreventing excesslve increase of currentvalue when, owing for example to the pres so adjusted as to maintain the proportion,

between the current-values in the windings 0 and d respectively, required for normally causing the pole pieces :0 to be repelled and held apart from the pole piecesd as will noW- be described .with reference to Fig. 1;

That is to "say, in normal circumstances ('5. a. when no train is in the'block 'section, and no other abnormal current-conditions prevail), current flows from the positive pole of the battery e, through the Wire 11, resistance m, rail a, wire 12, windingd, and Wired/ back to the negative pole of the battery'@, thus energizing the winding dot the relay. At the same timercurrent also flows fromthe positive pole of the battery 6, through the wire 0 winding 0, wire 14, and

wire 13, back to the negative pole of the bat-e tery 6, thus energizing the Winding 0 of the relay. The respective coils of the relay are so wound that, so long as the conditions just described prevail, each of the poles al has opposite to it a'pole 0 of-the same sign, so that-the movable poles c are repelled and held apart from the stationary poles al in opposition to gravity or spring pressure. Consequently, the switches h and j are closed and'the signal f is held at-line clear, as

indicated injFig. 1.

e If, now,-as indicatedin Fig. 2, an axle and Wheels 70 enter the block-section, it will be seen that whereas, onthe' one hand, the

- circuit of the battery 6 through thewinding c of the relay remains substantially unaffected, current still'flowing from the positive poleof the battery through thewire 0 winding 0, wirell, rail 6, and Iwir'e-13-back to the negative pole ofthe'battery, on the other hand the presence, of the axle and wheelsk'has foreti'ect to cut ofi' current, 'partiallyor wholly, from the Windingv d of the relay, current now'flowing from the positive poleof the battery 6 through Wire 11, resistance on, part. only of the length of raila, the wheels and axle k, the corresponding part only of the length of rail 7), and

wire 18,back'to the negative pole of the battery. -',Hence,the winding (Z being partially or completely deenergized, the magnetic field between the pole-p'ieces, d becomes weakened or ceases to exist, so that the repulsive effort previously "maintained as between the pole-pieces (Z and 0 either ceases altogether or is so reduced as to be no longer capable of overcoming the gravityor springpressure under which the pole-pieces c tend to approaclrthe pole-pieces (Z with the re caused to vary beyond what'may'be termed the working-limits ofsaid ratio; hfioreover, as any lsuch disturbance of the current-conditionswithin the system (as distinct from total cessation of curreiitfin both windings of the relay) will produce a corresponding alteration in the strength 'of the magnetic field normally existingbetwemi the polepieces of the one "winding relatively 'to the strength of the field normally existing between the pole-piecesbit' .theother winding, the result of the rdisturbance 'inay 'even'be that'the attractive influencev of that mags netic field which tends to draw the pole piecesc toward the pole pieces al may become 'so much more powerful thanthe re pulsive influence of that field whiclrtends to separate said pole pieces, that the attractive influence; of they fir t mentioned mag netic field will cooperateuvitli grayity or spring-pressure in holding-the pole-pieces 0 positively inrvposition to keep the switches ..h andy'openp f. 5' I w i It will be observed that the arrangement as a whole involves the use not ofoa trackcircuit- (in the #ordinary) or accepted sense of a circuit 'wlie1'eof=both:rails of the track, being constantly in series with one another, normally form portion), but of'twodistinct rail-circuits whereof the-individual track rails a and :b, respectively form parts in series with the respectivewindings (Z and 0 of the relay; these rail-circuits being, normally, mutuallye independent though supplied witlrcurrent from a single source 6, andthe circuitof said sourcebeing closed through both track-railsa and inrseries with one another only when saidrails' are electrically connected together,*' as for example in consequence-of .the'presence of a train in the'block-section as atzk; iv 1 whereof the opposite polesaareconnectedito the respective track-r'ail's-at -one end of the -blocksecti0n,.a relay, two separate -Windthat track-rail which is connected to the other pole of said source, and pole-pieces for each winding of the relay, the pole-pieces of the one winding being opposed to and movable toward and from the respectively adjacent pole-pieces of the other windin and the respective windings being woun for producing normally a state of magnetic repulsion between each pole of the one winding and the opposed pole of the other winding. a p

2. In a system of electric control for railway traffic, the combination of a pair of track-rails, a source of electric energy whereof the opposite poles are connected-t0 the respective track-rails at one end of the block-section, an electric resistance interposed in series between one of said trackrails and the connected pole of said source of current, a relay, two separate windings on said relay each of which is connected in series between one pole of said source of energy and the opposite end of that track rail which is connected to the other pole of said source, and pole-pieces for each winding of the relay, the pole-pieces of the one winding being'opposed to and movable toward and from the respectively adjacent pole-pieces of the other winding and the respective windings being wound .for producing normally a state of magnetic repulsion between each pole of the one winding and the opposed pole of the other winding.

3. In a system of electric control for railway trafiic, the combination of a pair of track-rails, a source of electric energy whereof the opposite poles are connected to the respective track-rails at one end of the block-section, an electric resistance interposed in series between one of said trackrails and the connected pole of said source of current, a relay adjacent to the opposite end of the block-section, two separate windings on said relay, one end of each winding being connected to the adjacent end of one of the track-rails, insulated conductors for connecting the other ends of the respective windings with the respective poles of the source of energy, and pole-pieces for each winding of the relay, the pole-pieces of the one winding being opposed to and movable toward and from the respectively adjacent pole-pieces of the other winding" and the respective windings being wound for producing normally a state of magnetic repulsion between each pole of the one winding and the opposed pole of the other wind in a i. In a system of electric control for railway traflic, the combination of a pair of track-rails, a source of electric energy whereof the opposite poles are connected to the respective track-rails at one end of the block section, an electric resistance interposed in series between one of said trackrails and the connected pole of said source of current, a relay, two separate windings on said relay each of which is connected in series between one pole of said source of energy and the opposite end of that trackrail which is connected to the other pole of said source, pole-pieces for each winding of the relay, the pole-pieces of the one winding being opposed to and movable toward and from the respectively adjacent pole-piecestrack-rails, a source of electric energy wherep of the opposite poles are connectedto the respective track-rails at one end of the block-section, an electric resistance interposed in series between one of said trackrails and the connected pole of said source of current, a relay, two separate windings on said relay each of which is connected in series between one pole of said source of energy and the opposite end of that track rail which is connected to the other pole of said source, pole-pieces for each winding of the relay, the pole-pieces of the one winding being opposed to and movable toward and from the respectively adjacent polepieces of the other winding and the 're-' spective windings being wound for producing normally a state of magnetic repulsion between each pole of the one winding and the opposed pole of the other winding, an

electrically-controlled signal, a source of electric energy for operating said signal, and electric switchesinterposed in series between said source of energy and the signal,

7 said switches being normally held closed by the movable pole-piecesof the relay.

REUBEN WILLIAM TARRANT.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Iatents,

. Washington, D. G. 

